In this article, the authors describe professional growth of three Dutch teachers during the development and subsequent class enactment of student learning material for a context-based chemistry curriculum. This network consisted of three experienced chemistry teachers and A male coach employed by the teacher training department from a university was chair of the network. The results show that the development of learning material can be seen as a training program to prepare teachers for an innovation. Furthermore, teachers’ knowledge increased in all five pedagogical content knowledge domains during the development and class enactment phases.